G.J. wrote:
> Two items:
>
> 1."Ignitor" vs "Crane" EI. any comments? The "Ignitor" is
> cheaper (MOSS), and is totally encased under the distributor cap.
> Overheating problems? opinions ,experience, anyone?
Greg:
I've installed the Crane 3000 model. The installation was easy, it's mounted
in the engine compartment with an optical sensor which mounts in the
distributor.
It has a nice large heat sink on it, and I've had it running in 105 F without
problems. I would recommend it as there is not much space in the distributor.
It requires that you leave the mechanical and vaccuume advance mechanisms in the
distributor. However, I think that they have a 9000 model which allows you to
set your advance curve on the unit, and then you don't need the mechanical
advance.
But it's $$$.
>
> 2. I installed a Piper "fast road cam" (valve lift .400", duration: 272
> intake,270 exhaust) and higher-than-stock compression pistons in my 72
> MGB engine during its rebuild. I'm not getting nearly as much performance
> as I expected to get with these modifications. I beleive my HIF carbs are
> performing well(although I'm rebuilding HS4's so I can use them for the
> vacuum advance)...note: emmissions have been totally removed...I was
> using a direct line from the VA to the intake manifold, but was told that
> it will advance my timing at incorrect times (I still don't understand
> why and when you want vacuum advance). It appears the distributer I have
> is from a 64-67 (#40897). Could this be the problem? Could the
> mechanical advance weights be incorrect for my application?
>
I have some sort of fast road cam in my 72 GT, and I think that when you have
a fast road cam, that you need to adjust the valves to have different clearences
than stock. Is this true? What do you have your valves adjusted for? I also
have
a direct line from the intake manifold to the vaccuume advance. My car seems to
run fine, but I've never been in a stock one to compare. I also have a tuned
exhaust
header. I do have one problem, and that is that when I'm cruising at freeway
speeds,
sometimes it seems to surge like it's not getting enough gas. I think that I
need
different needles than stock dual SU's have. Any tuning help out there on the
net,
or that you find would be appreciated. (btw, I've been told that about the
only
way to pick the right needles is on a rolling dyno, but I haven't found a local
shop which has one, and that knows about SU carbs.)
Dave Hall
dhall@vcd.hp.com
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